Drilling machine



5 Sheets-Sheet 1 Inverr.- 6H 612321109114 Mx *IM-APH Y 8.

lli f gg Feb. 7, 1928.

G. H. GILMAN DRILLING MACHINE w b bm m,

Feb. 7, 1928.

G. H. GILMAN DRILLING MACHINE Filed Nov. 4, 1920 5 Sheets-Sheet 2 G. H.GILMAN DmLLING MACHINE Feb. 7, 1928.

Feb. 7, 1928.

G. H. GILMAN DRILLING MACHINE Patented Feb. 7, 1928.

UNITED STATES GEORGE H. GILHAN, OF BOSTON, MASSACHUSETTS.

DBILLING MACHINE.

Application filed November 4, 192D. Serial No. 421,748.

My invention relates to drilling machines and more particularl but notcxclusivelyto those for drilling roch' and operated by fiuids underpressure.

My invention will be best understood from the following description whenread in the light of the accompanying drawings of one speciticembodiment of my invention selected for illustrative purposes, while thescope of my invention will he more particularly pointed out in theappended claims.

In the drawings:

Figure 1 shows a longitudinal section ot the submitted embodiment of myinvention, parts heilig broken away;

Fig. 2 is a section on the line of Fig. 1;

Figs. 3 and 4 are sections respectively on the lines 3-3 and 4--4 ofFig. 2:

I `igs. 5, G, 7 and 8 are respectively sections on the lines 5 5, 6 6,7--7 and 8--9 of Fig. l; l

Figs. 9 and 1() are respectively sections on the lines 9-9 and 10-10 ofFig. 2;

Fig. 11 is a plan view of the carriage for adapting the drillingmechanism to the cradle of the feed mechanism;

Fig. 12 is a section on the line 12M-1; ot` Fig. 11;

Fig. 13 is an end elevation ot Fig. 1l;

Figs. 14 and 15 are diagrams illustrating the operation of the submittedemlmdimcnt of my invention;

Fig. 16 is a diagram showing some of the connections to the throttlevalve; and

Figs. 17 and 18 are diagrams respectivel v illustratin{ r the throttlevalve in its throttling and off positions.

Referring more iarticularly to Figs. 1 to ltl. the rock drill 1n thesubmitted embodiment of mv invention comprises a drill steel I andmechanism for operating the same hy imparting percussion thereto androtating it.

For imparting percussion to the drill steel I have illustrated a pistonhaving a body portion or head 2 of large diameter and projectingtherefrom. a hammer bar fl, the front end of the latter being adapted tostrike the rear end of the drill steel at the end of the forward strokeof the piston. As shown the piston is further provided with a rearwardextension 4 of smaller diameter connected to the body portion Q by meansof'- the reduced diameter portion 5. Surrounding Dwi) the piston is -acasing herein comprising a cylinder member 6 having a forward bore 7 oflarge diameter for the large diameter portion 2 of the piston and arearward cylinder member having the bore 8 of smaller diameter for thesmall diameter portion of the piston.

As illustrated the rearward cylinder member comprises a block 9 forminga closure for the larger bore 7 and carried thereby a rearwardlyextending member 10. 'The member 10 herein is provided with a flange 11'which abuts the rearward face of the block 9 and at its forward end isprovided with a cylindrical portion 12 which enters the bore 13 of theblock 9. For maintaining the extension 10 and block 9 in fixed angularrelation I have shown the dowel 14, and for maintaining the same inassembled relation I have shown the end of the portion 12 as upset intoa counter-sunk portion at the forward end of the bore 13 as indicated at15. Herein integrallv formed with the extension 10 is a rear cylinderhead 16.

The drill Steel is carried by the chuck 16 in any suitable mannersutlicient to cause rotative movement of the chuck to be imparted to thesteel. Herein the chuck has an exterior hearing 17 in the chuck casing18 and at its rearward end an exterior hearing 19 in the front cylinderhead 20. On the exterior portion of the chuck intermediate the bearingsare illustrated gear teeth Q1 and meshing therewith the internal gearteeth of the yokes Q2. These vokes operate to form a reduction gearingand for driving the same I have shown a rotar)v motor comprising theintermediate gear member Q3 and the side gear members 24. Driven b v theside gear members are the shafts Q5, each of which in the presentembodiment of my invention carries a pair of eccentric members 26, whichwhen the shafts are rotated act to gy ate the yokes and thus to rotatethe drill awel. For connecting the shaft-s to the rotors I have shownkeys 25 carried by the shafts entering suitable ways in the gear members24. The keys are of such dimensions that the shafts may he drawntogether with the keys through the shaft bearing blocks 3Q and 321. Ingeneral the details of the chuck rotating motor and gearing 'form nopart of the invention to which this application is directed and then`-fore will not be described with more particlll ularity than is necessaryto show how they are applied to the invention under consideration.

The intermediate gear member 23 of the chuck rotating motor surroundsand is journalled on that portion of the c linder extension 10 which isrearward o the block 9. For housing the operative parts of this motor Ihave shown a casing which comprises a lateral portion 27 and an endportion, the latter comprising for a purpose hereinafter to be describeda sleeve 33 on the exterior surface of which is mounted the body 28 ofthe end casing. The sleeve 33 of the end casing is shown as providedwith a flange 34 against which the forward portion of the bod abuts, andfor holding the parts in assem led relation the end of the sleeve isshown as upset into the counter-sunk portion of a body as is indicatedat 35. For holding the motor and its casing in position I have shown anut having the screw threaded ortion 36 which enters the bore 37 formein the rear cylinder head 16 and cooperates with screw threads formed onthe interior portion of such bore. This nut is shown as provided with alian e 38 adapted to abut against the rearward ace of the end ortion ofthe chuck rotating motor casing w en the nut is screwed into position.

As illustrated by Fig. 2 for sup orting the intermediate ortion of eachsha t 25 I provide the antiriction bearings 32 and 32a respectivelycarried in suitable recesses in the block 9 and the front cylinder head20. For supporting the ends of the shafts I have shown a rearwardbearing in the block 32b carried in a suitable recess in the motorcasing member 28 and a forward bearing 32 forined in the chuck casing.Herein the blocks 32 and 32" respectively are formed with flanges 31 and31", the flan e 11 of the cylinder extension as illustrate by Fig. 9bein cut away to receive the flange 31, and the ange 31" as illustratedby Fi 1() being cut away to receive the flange 34 o the sleeve 33 of themotor casing. By this construction are provided smooth surfaces for theend faces of the motor gear members and a shoulder afforded by the ed esof the respective flanges over which I t the motor casing member 2T andthereby dowel the same to ositon it angularly. Further the bearing lock31 serves to position and doivell the extension 10 in its roper angularrelation to the block 9; whi e the block 32h, which carries theautomatic lubricator hereinafter to be described, similarly positionsand dowels the motor casing parts, 27, 28 and 33 to each other.

For holding the cylinder sections encasing the piston in assembledrelation I have shown the side bolts 39. These side bolts preferably areof such number and are so arranged that two of them are located at oneside of a plane passing through the longitudinal axis of the machine,the purpose of which will be hereinafter described. These bolts I haveshown provided with heads 40 engaging the chuck casing and nuts 41engaging the rearward face of the chuck rotat'ng iuotor casing. It willbe observed that by removing the nuts 41, the sections of the cylinderinay be separated and that the rearward portion of the cylinder togetherwith the chuck rotating motor may be removed as a unit.

I have shown the drilling machine as provided with a suitable feedmechanism which herein comprises the cradle 42 having the ways 43, andthe feed screw 44. Carried by the ways in slidable relation thereto isshown the carriage 45 provided with the guide members 4G cooperatingwith the ways on the cradle. The carriage herein is provided ivitliupstanding members in the form of ears 47 which as shown are four innunibei'. These ears are perforated as indicated at 48 to receive thoseside bolts 39 which are adjacent the carriage and herein the casing isrecessed as indicated at 49 and 50 to receive such ears. As indicated inFigs. 1, 5, 6, 7 and 8 the adjacent ortions of the carriage and casingare fini ed to provide flat contacting surfaces for better holding theparts in rigid assembled relation. It will ie appreciated that byremoving the two side bolts extending through the ears of the carriagethe drilling machine niay be removed from the carriage withoutdisassembling the drilling machine.

As hereinbefore described, in the present embodiment of my invention theportion 12 of the cylinder section eiicasing the rear piston extensionis provided with a surface which fits the bore 1.3 of the ineniber 9 andlikewise the exterior surface 0f the sleeve :lll fits theinteriorsurt'aceof the bodyY portion of the end casing and the motor. Inthese surfaccsas illustrated by Figs. l and :2 are foi-ined annulargrooves 51, 52, 53, 54 and 55. Herciii the groove 51 forms au oilreservoir and the grooves 52 and 53 respectively forni conduits fordistributing the adiuisison motive fluid and exhaust motive fluid to andfrom the chuck rotating motor while the grooves 54 and 55 forni part ofthe fluid 'distributv ing passages for reciprocating` the piston. Asillustrated by Figs. 1 and 10. the motor is provided at theVintersection of the boresl 29 and 30 willi the admission passages 5i'and at the opposite intersection as illustrated by Figs. 5 and 9, withexhaust passages 56. F or convenience of illustration. these passagesare shown in Fig. 1 by dotted lines somewhat out of position, the trucpositions being indicated by Fins. 5, 9 and 10. llie `n'roovt` 5:2 isconnected v means of a conduit 5S with the motive fluid inlet 59 and thegroove 53 by means of the conduit 30 till with the atmosphere in amanner hereinafterwards to be described. The purpose of employing theannular roo'.es will he appreciated from the consideration of theconduits admitting motive fluid to the motor. `In this connection itwill be observed that the supply conduit 58 is on the top of the machinewhile the conduits 57 are angularly positioned with reference theretocircumferentially around the axis of the machine. Hereinbefore in suchconstructions it has been usual to drill intersecting passages in thewall of the cylinder which as understood by those skilled in the artnecessitates the use of plues to close the ends of the holes thusdrilled and the forming of bosses or thickened portions on the cylinderwall to provide material for drilling the passages. By the constructionherein set forth, the manifest disadvantages of the prior constructionare avoided.

Referring to Figs. 1, 2, 3, 4 and 6, I have illustrated the groove 55 asconnected to a motive fluid supply passage 6l and with the forwardportion of the rearward bore by means of oppositely disposed passagesG2, while the groove 54 is shown as connected to the forward portion ofthe reaward bore by means of oppositely disposed passages 63 and to theforward end of the larger bore by means of a plurality of passages 64,one of which is shown in Fig. 1 out of angular position for convenienceof illustration but the true position of which is illustrated by Figs. 3and 6. Extending rearwardly from the passages 62 I have shownlongitudinal grooves G formed in the interior surface of the smallerbore and terminating in the plane of the passages (Sil. Bv thisconstruction, when the piston is adjacent the rearward end of the strokeas illustrated by Figs. 1 and 14, the motive fluid admitted to thegroove 55 passes into the rearward end of the cylinder bore of largediameter through the passages ($2 and the passage all'orded by thereduced diameter portion 5 of the piston; and when the piston is in itsforward position as shown by Figs. 2 and' 15, the motive fluid passes byway of the passages 62 and G5 from the groove 55 into the smaller pistonbore. whence it finds its way into the forward end of the largercylinder bore' through the passages 63, the groove 54 and passages 64.When the piston moves ,forwardly from its rearward position, the snpplyto the rearward end of the larger cylinder bore is interrupted and whenit moves rearwardly from its forward position the supply into therearward end of the smaller bore and the forward end of the larger boreis interrupted.

In the present embodiment of my invention the motive fluid admitted atthe end of the forward stroke into the rearward portion of the smallercylinder bore is cut oif when the piston in its rearward movement closesthe orts 65 and after this the motive fluid by tie continued rearwardmovement of the piston is trapped and compressed above its initialpressure. During the forward stroke the pressure of the motive fluid atthe rear oi the piston extension l materially increases the energyimparted to the piston and this aids in producing a heavier blow than ifmotive fluid at initial pressure were utilized in the smaller bore forproducing the forward stroke.

In the intermediate portion of the cylinder as illustrated by igs. 1 and6 I have shown a slot 66, which serves as a piston controlled exhaustport and as will be clearly understood by those skilled in the art. thisport permits the lnotive fluid to be alternately exhausted from thcopposite sides of the piston portion 2 when uncovered therebv during itsreelproeat|ons. Formed in the wall of the cylinder I have shown a pairof longitudinal passages 6T which intersect the slot 66 and are adaptedto be placed in communication with the atmosphere in a mannerhereinafter described.

llesides the valveless fluid distributing features so tar described lmay also provide additional fluid distributing means in the form ot' avalve. As will be understood by those skilled in the art, the iniddistribution directly controlled by the pistou` such usually beingItermed a valveless distribution. has the advantage of quit-lil)Y admit'-ting and exhausting motive fluid, but has the disadvantage that anearl),v point ot' eut-oil' and compression must be provided. ()n theother hand. when the iiuid distribution is controlled .solely b v avalve these advantages and disadvantages are reversed. By properlycombining' the two formsl of distribution. the disadvantages of each maybe eliminated and the advantages of both re tained, which is to say thatb v means ot' the valveless distribution the quick admission and releasemay be obtained and by means of the valve the mean etleetive pressuremay be increased by making the effective point of ent-oli' andcon'ipression lute in tbe stroke. The valve. in the submitted embodimentol my invention controls admission and exhaust of fluid to both sides ofthe pistou portion for both its strokes. although as will be obvious.the admission or exhaust events controlled by the valve for the fluidused at either side of the piston portion 2. may be omitted. It may,however. be pointed ont. that owing to the compression of the [luid inthe chamber 8 on the rearward stroke. either or both a late point ofcompression for the fluid exhausted at the rear of the piston portion 2and late point of cut-oli` for that ad mitted in front of this pistonportion is desirable. This application is not concerned with the detailsof the valve and therefore lill only so much of it as necessary for aclear understanding of my present invention will be described.

As showm'the cylinder is provided with a longitudinally arranged lateralenlargement 68 which receives the valve cage sections (if) and 70 forhousing the tubular valve T1 more fully described. The internal bore otthe valve cage is provided with a conduit 72 adapted in a mannerhereinafter described, to be placed in connection with the source ofmotive fluid supply and is also provided with thc annular grooves 73,74, i5. 76 and 77. The exterior surface of the valve is provided withthe circumferentially arranged flange 78 and the grooves 79 and 80. Theannular grooves 74 and 76 just referred to are connected by means ofpassages 8l and 82 with the exhaust passages 67, while the grooves 71.5and 77 respectively are y connected hv means ot passages 83 and 84 withthe cylinder bore of larger diameter adjacent its opposite ends. Theflange 7S of the valve fits in a fluid tight manner the Ainteriorsurface of the annular groove 75 of the valve casing and extending fromop posite ends of the groove 75 to the interior of the enlarged bore ofthe cylinder are the crossed kicker passages 85 and 86. As will beunderstood by those skilled in the art. when the piston reciprocates,motive Huid is alternately admitted and exhausted by means of the kickerpassages 85 and 86 to the annular groove 75 of the valve casing to actupon the Harige 78 of the valve to cause the valve to be thrown toopposite ends of its travel.

The operation of the parts described for controlling the fluid causingthe piston to reciprocate is as follows:

lVhen the pistou is in the rearward portion of its stroke as illustratedby Fig. 14, the valve has been moved by the fluid admitted by the kickerport 86 to the forward end of its travel. In this position of the parts,assuming the motive fluid is admitted through the passages 61 and 72respectively to the groove and to the interior of the valve. motivefluid will How from the groove 55 by way of the pasasges 62 and aroundthe reduced portion 5 of the piston into the rear of the largercylinder-.bore and when the piston portion 2 uncovers the passage 83leading from the valve cage, motive fluid will be admitted from thepassage 72 by way of the groove 73 and passage 83 into the rearward endof the cylinder portion of large diameter. In this position 'of theparts, the piston has uncovered the exhaust slot 66 which permits thevmotive 61nd in front of thepiston to exhaust throu hV said slot intothe passage 67 whence it ds its wav to the atmosphere. Also motive fluidin front of the piston may pass through the passage 84, the groove 77 ofthe valve cage,

Lesaaso the groove 80 of the valve, the groove 76 of the valve cage, andthe passage 82 into the exhaust passages 67.

When the piston reaches the forward end of its stroke as illustrated byFig. 15, the valve has been thrown to the rearward end of its travel bymeans of motive lluid admitted through the kicker passage 85. After thepiston moves backward owing to its rebound far enough to uncover theforward end of the passages 64 and the passage 84, motive fluid isadmitted to the forward end of the cylinder bore ol' large diameter fromthe groove 55 by way of the passages 62, roove 65, passages (S3, annulargroove 54 an passages 64 and likewise from the passage 72 through theinterior of the valve, the groove 77 in the valve cage and the passage84. As the piston moves rearwardly, the motive Huid` in iront of theenlarged piston portion 2 passes through the slot G6, to the passages 6Twhence it finds its way to the atmosphere. Motive Huid as the pistonmoves rearwardly, also exhausts into the passages 67 by way ot' thepassage S23, groove 73 in the'valve cage, groove 79 in the valve, groove74 in the valve cage and passages 8l. At the end of the forward stroke`when the cylinder bore of smaller diameter has been expanded by theiston, the clnunber formed thereby is filled) with live motive fluidwhich passes from the groove 55 thereto by way of the passages 62 andand when duringthe rearward stroke, the passage 65 is closed, thismotive fiuid is trapped between the rearward end of the piston portionof smaller diameter and the rear cylinder head, which compresses theHuid to a high degree of fessure when the iston reaches the rearwar endof its stroke. The energy thus stored u in the compressed motive lluldis available or impartinv to the piston a greater momentum on itstn'ward stroke than if mot-ive Huid at initial pres-l sure were used inthe rear piston chamber of smaller diameter.

Motive fluid is led to the machine through a suitable air hoseconnection shown at 87 which conducts motive fluid to the intake 59. Forcontrolling the motive fluid I may use any suitable valvular mechanism,as for example the valve illustrated by Figs. 1,14, 15, 16, 17 and 18.This valve is in its general aspects of the usual turning-plug type.Formed in the valve is a longitudinal passage 88 and communicatingtherewith the radial passages 89, 90 and 91. In the full open operatingposition of the valve as illustrated by Figs. 1 and 14 the passage 89 isin communication with the motive fluid supply connection 59, whichdelivers motive u'id to the assage 92 lending to the valve cage conduit2 and to the assage 61 leading' to the groove 55. Throug the wall of theportion of the block 9 constituting the throttlc valve casing arepassages 93 in commuand 18. Fig. 16 shows a p monaco nication with theatmosphere and a pair of passages 94 in communication with the exaustpassages 67. In the operating position of the valve,the communication isestablished between the passages 94 and 93 by means of the exteriorrecesses 95, formed in the valve. 0n the exterior portion of the valvein communication with one of the receases 95 is an arcuate slot 96 whichin all positions'of the valve is adapted to be in communication with thepassa e 60 conducting exhaust motive fluid from t 1e chuck rotatingmotor. This motor is supplied with motive fluid through the -connectlon97, which communicates with the intake connection 59 in advance of thethrottle valve and in this manner the motive fluid is always admitted toand exhausted from the chuck rotating motor irrespective of the Hositionof the throttle valve. For' contro ing the chuck rotating motor I mayprovide a suitable throttle valve 98 carried by the chuck rotatingmotor, casing. y

For conducting water to the drill bit, I have shown a water tube 99which herei n communicates with the boreI 100 of the -bit and issupported at its rearward end in the rear c linder head 16. For securingthe water tulie and forming a water ti ht loint at the rear head, I haveshown a pac infr 101 of rubber orthe like which is positioned in thecavity- 37 of the rear head and surrounds the rearward end of the `watertube. When the nut 36 is screwed into position the packing 101 iscompressed and thus securely clamps and acks the rearward end of thetube. Herein the nut is provided with a passage 102 which at itsrearward end is enlarged and provided with securing means for the waterhose connection 103.

For supplying the bit with air, I have shown a passage '104, shown inFigs. 1, 7, 14 and 15, in communication with one of the exhaust passages67 or if desired I may provide two passages 104, each in commun1ca tionwith one ofthe passagles 67. For supplying the passage 104 wit air toblow the hole, I have shown the throttle valve as pr vided with apassage 105 in communication with the interior conduit 88 of the valve.Herein this assa e 105 terminates on the exterior of tie va ve in thesame lane as one of the passages 67 so that when t e valve is turned tointerrupt communication between the exhaust discharge 93 and the exhaustpassage (i7, the passage .105 will be brought into communication-withthe passage 67 `and therefore fill the interior of the machine with liveair which linda its way throu h the passa es 67 and 104 to the interioro the chuck c amber and hence into the boreo the drill steel.A f rTheoperation of my throttle valve will .be best understood from Figs. 1415, 16, 17

an o the valve corresponding with the section shown in Fig. 1, with someof the connecting passages shown diagrammatically by dotted lines. In Fis. 14, 15, 17 and 18, the valve is represent by three sectionsrespectively on the lines a-a, 12-6, c-o of Fig. 16. Fig. 14 shows thefull open running position, Fig. 15 the hole blowing position, Fig. 18the throttling position and Fig. 17 the of or inoperative position.

In the position of the parts, illustrated by Fig. 14, the motive Huid isadmitted from the intake connection 59 through the throt tlc valve tothe passages 92 and 61 to the valve and valveless distributing means ofthe permissive mechanism, while the exhaust from the same is conductedfrom the passa 67 through the exterior slots 95 of the va ve to theexhaust discharge 93. In this position the -passaggi 105 is blanked andtherefore the hole is not blownand the piston reciprocates. Motive uidis led through the passage 97 from the intake connection 59 and passes,if the valve 98 is open, into the groove 52 whence it is distributed bythe passages 57 to the chuck rotating motor. Motive fluid after passingthrough the chuck rotating motor exhausts through the passages 56 intothe groove 57 whence it passes to the atmosphere through the passage 60and arenal groove 96 on 'the valve plug to -the exhaust discharge 93.

When the hole is to be blown, the valve is moved to the position shownby Fig. 15. Under these conditions, the exhaust discharge 93 is out ofcommunication with the passages 67 and the live air passage 105 of hevalve is brought into communication with one of the passages 67 whichadmits motive iuid thereto and discharges the same, through the passage104 into the chuck casing whence it finds its way into the bore 100 ofthe steel. Under these conditions, the passages 90 and 91' are out ofcommunication with the intake conduits leading to the percussiveapparatus but obviously with the ordinary form of valve motion it willbe suicient if these passages remain in communication with the intakepassages; providing the exhaust is closed. It, however, is desirable tocontrol the motor By more or less throttling the intake and for this purpose the orte and passages are so construct ed that t e intake may bethrottled to control the blow before the exhaust is closed. Such aposition is shown by Fig. 18 in which it will be noted thatthe exhaustis open and that the admission to the passages 92 and 61 is throttled.Bv turnin the valve slightly from thls position the" egree of throttlingcan be increased' or diminished.

When the machine is to be placed out of operation, the valve is turnedto the position illustrated by Fig. 17, which shows the passage 59supplying motive fluid closed. From this position the valve isprogressively turned in the same direction to the-positions illustratedby F ig. 15. in which the hole is blown, that illustrated by Fig. 18 inwhich a Small supply ot air is admitted to operate the machine to strikea light blow, and finally that illustrated by Fig. 14, in which a fullsupply of air is admitted to the hammer. The valve is moved from thislast position in a reverse direction to throttle the hammer, blow thehole and finally to sluit olf the air.

It will be observed in all positions of the valve the exhaust from thechuck rotating motor is not affected and the same irrespective of theposition of the valve may be regulated or put out of operation by meansof the throttle valve 98.

As has heretofore been pointed out. iu the present embodiment of theinvention the bearing blocks (2b carry automatic lubricators and as thelubricator carried b v each is similar, only one will be described. Asillustrated, formed transversely in the block is a cylindrical bore 106which communi- Cates with the exterior of the motor housing through anopening 107 in the motor housing member 28. Slidably mounted in the boreI have shown a cylindrical plunger 108 which is provided with theintermediate grooves forming chambers 109 and 110. Connect-ing the oilreservoir provided by the groove 51 with an intermediate portion of thebore 106 is a passage 111 and connecting the end of the bore with thegroove 52 supplying the/chuck rotating motor with motive fluid is apassage 112. In the [osition shown by Fig. 2, oil is conducted from .theoil reservoir by way ot the passage 111 to the chamber of the lnbricatorplunger and when the plunger is moved to the opposite end of its travel,this chamber is placed in communication with the oil distributingpassage 113 andthe chamber 109 of the plunger brought into communicationwith the passage 111 and when the plunger again moves to the positionshown b v Fig. 2, the oil which has entered the latter is dischargedinto the distributing passage 114 and the chamber 110 again filled.Herein the plunger is held inthe position Ishown by Fig. 2 by means of aspring 115 interposed between the end of the plunger and the plug 116closing the bore 107.. When motive fiuid is admitted to the groove 52,the pressure thereof acting through the passage 112 on the end of theplunger overcomes the force of the spring and moves the plunger to theopposite end of its stroke and when the supply to the groove 52 isinterrupted, which results in the .elimination of the pressure of themotive uid on the end of the plunger, the spring moves the plunger tothe position shown by Fig. 2.

As illustrated, the passage 113 communicates with the passage 117extending throughout the length ot' the shafts 25 and oil dischargedinto said passage is distribut,

ed by means ot radial passages 118 establishin communication betweensaid passage and t e exterior of the shaft to the shaft and eccentricbearings. Oil which is admitted to the passage 114 finds its way throughsuitable connecting passages to grooves 119 formed on the exteriorsurface of the cylinder extension 10 and serves to lubricate the bearingfor the central rotor of the chuck motor. Some of the oil admitted tothe passage 113 tinds its way around the rearward end of the shaft tolubricate the end bearing of the shaft and from this bearing into theinterior of the chuck rotating motor and in a like manuel' .some of theoil admitted to the groove 119 finds its way into the interior of thechuck rotating motor. The oil thus admitted into the interior of thechuck rotating motor serves to lubricatc the gear teeth.

As will be understood bv those skilled in the art and as will be obviousa suitable filling orifice in communication with the eX- terior of themachine and provided with a suitable closure will be employed toreplenish the oil supply for the groove 51.

The valve and other features herein shown are claimed in applicantsco-pcnding applications Serial No. 113,672, tiled June 4. 1920 (which isa division of application Serial No. 386,868, tiled June '5, 1920. onwhich United States Patent 1,588,407 was granted to applicant June 15,1926), and Serial No. 76,410, filed December 19, 1925 (which is adivision of this application).

It is to be understood that although I have described one specificembodiment of my invention for illustrative purposes extensivedeviations from the same may hc made without departing from the spiritot' the invention.

Claims- 1. In a rock drill, a piston. a sectional casing for saidpiston. means for securing the sections of said casing in assembledrclation, a chuck, a motor for rotating said chuck, said motor carriedby one of the piston casing sections and having a casing separate andremovable from said piston casing, and means independent of said meansfor securing the piston casing sections in assembled relation forsecuring the motor casing to said piston casing section whereby the lastnamed section can be removed with the motor as a unit.

2; In a rock drill, a piston having a hammer portion of lax' er diameterand an extension of smaller diameter, a casing section for said pistonportion of large diameter, a separate casing section for said portion ofsmaller diameter, a chuck operating moloo lPo

tor com rising a fluid operated member surroun lng said separate casingsection, a. separate casing for said motor, means for securing saidcasing sections for said piston portions in nonrotatable relation, andmeans for securing said 'motor eosin# to said separate casing sectionwhereby t e latter may be removed with said motor as a unit.

3. In a rock drill, a hammer .piston having an extension, a sectionalcasing for said piston comprising a se arate section for said extension,said section having anexteriorly reduced portion, a chuck' rotatin motorcomprising a rotor surrounding sai portion, a separate casing for saidmotor surrounding said portion, means for securing said motor casing tosaid separate section, and separate means for securing in non-rotatableassembled relation the sections of said piston casing whereb1 saidseparate section or said extension an motor may be removed as a unit.

4. In a rock drill, a liain'mer piston having an extension, a sectionalcasing for said piston comprising a separa te section for said`extension, said 'section having au exteriorly reduced portion, achuclrl rotating motor comprising a rtor surrounding said portion, meanscarried by said'reduced rtion for securing said motor casing to saiseparate section, and separate means for secnr. ing in nonrotatableassembled relation the sections ofv said piston casing whereby said4separate section and motor 'may be removed as Va unit.

Vli. In a rock drill, a hammer piston, u cylinder for said hammer pistonhaving a main body iortion, an end section for said cylinder forming aclosure -for said cylinder body portion and having a member projectingtherefrom. u chuck rotating motor comprising a rotor jouriuilvd on saidmember, a casing for said motor surrounding said member and carriedthereby, and nicnns carried b v said ineiiilicr for securing the motorcasing thereto.

(i. ln n rock drill, a hammer piston, a cylinder for said hammer pistonhaving a main body portion, un end section for said c linilw' forming aclosure for said cylinder indy rmi-tion and lhs-refrain, a chuckrotating motor comprising: a rotor iouriialcd on said member, a casingfor said motor surrounding isaid member and carried thereby, und saidinein ber having a screw threaded portion currying :i nut for securingthe motor casing to said member.

7. In a rock drill, a hammer pistou, a cylinder for said hammer pistonhavin a main body portion, an end section for said c linder forming nclosure for said cylinder ody portion and having a member projectingtherefrom, a chuck rotating motor compris- 'ing u rotor journaled onsaid member, a

having a nicml'ier projecting casing rfor said motor surrounding saidmember andcarrled thereby, said member having a screw threaded portioncarrying'a nut for securing said mot-or casing tosaid iuember, and acleansing lluid tube connected to said nut.

8. I n a rock drill, a hammer piston, a cylinder for said hammer istonhaving a main bod "portion, anen section for said cylinder ornii aclosure for said cylinder body portion an having a member project- ,ingtherefroima chuck rotating motor comprising a rotor y a casingforsaidmotor surrounding said ii'icmber and carried thereby, a cleansing 'luidconducting means, and said member having a screw' threaded portioncarrying a nut surrounding said conducting means for securing raidcasingto said member.

9. In a rock drill, a- -c rearward extension of uced diameter, a motorsurrounding said extension, means for .holdi said motor and cylinder inassembled re tion, feeding means for said cylinder, said feeding meanscomprising ears received in recesses infsaid c linder; side boltspassing throu li said cylinder, said motor and ears: an vsaid side boltshaving their nuts at their rearward ends whereby'said motor may bedisassembled without removing said cylinder from said feeding mechanism.A A 1 10. AJdrilling machine having, in combination, a hammer cylindercomprising separute sections, at least three side bolts for securingsaid sections to ether. a member for supporting said cylin er, pairs ofperforated ears on said member, und a. mir only of said side boltspussin through tie erforations of said ears, w iereby said cy inde-r maybe detached from said member while securing the sections of saidcylinder to-4 gether.

11. A rock drill, having in combination, u ercussivc motor comprising asectional 'cy indcr, u carriage for supporting said cyliiider, a supportslidably supporting said carriage, means for securing t e sections ofsaid cylinder together comprising a pair of side bolts at the side ofsaid linder adjacent said carriage, longitudinal y and transs vorselyaced ears on said carriage thi-on li which' said side bolts extend, andother si e bolts for securiii said sections together.

12. A rock drill havin in combination. a sectional hammer cylin erhaving a lurality of side bolts for securing the sections thereof inassembled relation, a feeding mechanism including a carriage in side toside relation with said cylinder, and means securin to part only of saidsaid carriage side bo ts, wliereb said cylinder may be detached fromsai' carriage while securing said sections together.

18. A rock drill, having in combination,

ournaled on said member,`

linder having a' lil) llKl

lll)

a chuck, a hammer pistou havin a rearward extension, a cylinder for saihammer piston having a body and a separate rearward section, the latterforming a cylinder portion for said extension, said rearward sectionhaving a reduced. exterior portion, a motor for driving said chuckhaving a rotor journalled on said reduced exterior portion andsurrounding said'rearward exten-Y wardV section, the latter forming acylinder` portion for said extension, said rearward section having areduced exterior portion, a motor for driving said chuck having a rotorjournalled on said reduced exterior portieri and surrounding saidrearward extensin of said piston, a casing for said motor surroundingsaid reduced portion, means for securing said casing to said rearwardsection, a feeding device for said cylinder having a slidably supportedcarriage, and common means independent of said means for securing saidcasing to said separate section for securing said separate section tothe body of said cylinder and said cylinder to said carriage.

15. A rock drill, having in combination, a chuck, a hammer iston havinga rearward extension, a cylinder for said hammer piston having a bodyand a separate rearward section, the latter formir:J a cylinder portionfor said extension, "said rearward section having a reduced exteriorportion, a motor for driving said chuckhaving a rotor journalled on saidreduced exterior portion and surrounding said rearward extension of saidpiston, a casing for said motor surrounding said reduced portion, meansfor securing said easing to said rearward section, a feeding devicecomprising relatively ymovable parts, side bolts independent of saidmeansfor's'ecuring said casing to V'said separate'sectionfor securn saidsepversely Vspacedears` at `each end of said carriage, recesses in saidc linder for receiving one armere of-sai pair of ears, said y side boltsintersecting said recesses, and the portions of saidearsreceived bysaidv recesses having perforations through which said side `boltsextend. t

17. A rock drill, having in combination, a cradle having a pairroflongitudinally disposed ways, a. cradle slidahly supported in said Ways,a ercussive hammer having a sectional cylin er supported on said.carringe, means for holding the sections of said cyhnder in assembledrelation com-prisng a air of side bolts at the side of said cyl in eradjacent said carriage, a pair: of transversely spaced ears at each endof said earriage, recesses in said cylinder for receiving one or more ofsaid pair of ears, said side bolts intersecting said recesses, and theportions of said ears received by said recesses having means forlocking` said ears to said side bolts.

InA testimony whereof, I have signed my name to this specification.

GEORGE H. GILMAN.

ill)

a chuck, a hammer piston havin a rearward extension, a cylinder for saihammer piston having a body and a separate rearward section, the latterforminer a cylinder portion for said extension, said rearward sectionhaving a reduced exterior portion, a motor for driving said chuck havinga rotor journalled on said reduced exterior' portion and surroundingsaid rearward extension of said piston, a casing for said motorsurrounding said reduced portion, means for securino said casing to saidrearward section, and-'means independent of said first named means forsecuring said separate section to said cylinder.

14. A rock drill, having in "combination, a chuck, a hammer pistonhaving a rearward extension, a cylinder for said hammer piston having abody and a separate rearward section, the latter forming a cylinderportion for said extension, said rearward section having a reducedexterior portion, a motor for driving said chuck having a rotorjournalled on said reduced exterior portion and surrounding saidrearward extension of said piston, a casing for said motor surroundingsaid reduced portion, means for securing'said casing to said rearwardsection, a feeding device for said cylinder having a. slidably supportedcarriage, and common means independent of said means for securing saidcasing to said separate section for securing said separate section tothe body of said cylinder and said cylinder to said carriage.

15. A rock drill, having in combination, a chuck, a hammer piston havinga rearward extension, a cylinder for said hammer piston having a bodyand a separate rearward section, the latter termin, a cylinder portionfor said extension, said rearward section having a reduced exteriorportion, a motor for driving said chuck having a rotor journalled onsaid reduced exterior portion and surrounding said rearward extension ofsaid piston, a casing for said motor surrounding said reduced portion,means for securing said casing to said rearward section, a. feedingdevice comprising relatively movable parts, side bolts independent ofsaid means for securing said casing to said separate section forsecuring said scparate section to the body of said cylinder, and spacedears on one of said parts of said feeding device having openings throughwhich said side bolts extend for securing said part to said cylinder.

16. A rock drill, having in combination, a cradle having a pair oflongitudinally disposed Ways, a cradle slidably supported in said ways,a ercussive hammer having a sectional cylin er supported on saidcarriage, means for holding the sections of said cylinder in assembledrelation comprising a pair of side bolts at the side of said cylinderadjacent said carriage, a pair of transversely spaced ears at each endof said carriage, recesses in said cylinder for rcceiving one or more ofsaid pair of ears, said side bolts intersecting said recesses, and theportions of said earsreceived by said recesses having perforationsthrough which said side bolts extend.

17. A rock drill, having in combination, a cradle having a pair oflongitudinally disposed Ways, a cradle slidably supported in said Ways,a percussive hammer having a sectional cylinder supported on said.carringe, means for holding the sections of said cylinder in assembledrelation comprisng a pair of side bolts at the side of said cylin eradjacent said carriage, a pair of transversely spaced ears at each endof said carringe, recesses in said cylinder for receiving one or more ofsaid pair of ears, said side bolts intersecting said recesses, and theportions of said ears received by said recesses having means for lockingsaid ears to said side bolts.

In testimony whereof, I have signed my name to this specification.

GEORGE H. GILMAN.

Patent No. l, 658, 330.

Granted February 7, 1928, to

GEORGE H. GILMAN.

ll is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 6,lines 125 and 126, claim 2, strike out the word "hammer" and insert thesame before the word piston in line 12S; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the ease in the Patent Office.

Signed and sealed this 3rd day of April, A. D. 1928.

M. J. Moore,

Acting nmmiginnnr nf Darn lll) CERTIFICATE OF CORRECTION.

Patent No. 1,658,330. Granted February 7, 1918, to

GEORGE H. GILMAN.

lt is hereby certified that error appears in the printed specificationof the above numbered patent requiring Correction as follows: Page 6,lines 125 and 26, claim 2, strike out the wurd "hammer" and insert thesame before the word piston in line 125; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 3rd day of April, A. D. 1928.

M. J. Moore, Acting Commissioner of Paten

